The present invention relates to an actuator arrangement for a motor vehicle drive train, having a control device, an actuator and a drive circuit for the actuator, which drive circuit receives at least one nominal signal relating to an actuator variable from the control device and converts it into a drive signal for the actuator, wherein the control device is checked for faults by means of a monitoring device, and wherein the drive circuit and/or a power stage which is arranged between the drive circuit and the actuator receives a reset signal when such a fault occurs.
The invention also relates to a corresponding method for operating such an actuator arrangement.
In automated motor vehicle drive trains, clutches are frequently activated by means of an electric motor. The clutches can, for example, be gear input-end friction clutches such as starting clutches. The clutches can, however, also be clutches for shifting gear speeds of a gearbox. In addition, the clutches can be embodied as friction clutches or friction brakes for an automatic torque converter transmission.
The known actuator arrangements include a control device which can be configured, for example, as a clutch controller or gearbox controller and which activates the clutch (and if appropriate further clutches) on the basis of a superordinate control strategy. The control device can be connected to a superordinate control unit, which is assigned to the drive train, and/or said control device can communicate with a drive control device for a drive engine of the drive train (for example an internal combustion engine or a hybrid drive). If faults occur in the control device, a monitoring device (for example a watchdog module) ensures that a reset signal is generated. The reset signal can be used to drive the actuator in such a way that the assigned clutch is placed in a basic state. This can be done, for example, by virtue of the fact that the drive circuit and/or a power stage receive a reset signal in the form of a deactivation signal.
The drive circuit is embodied as a circuit which is separate from the control device, for example as an independent microcontroller and/or as an independent circuit which is constructed with hardware components (for example using an ASIC module). Such modules can convert simple predefined nominal values into complex drive signals for the electric actuator.
The actuator can be an electric actuator such as an electric motor and/or an electromagnetic actuator.
Although the monitoring device which is provided for the control device already provides a high level of reliability, it is desirable to improve the reliability.